Study on the fine・cale mixing ・ chemical reaction process of matter in the liquid turbulent flows and the stochastic simulation method

The progress and results of the research are summarized in the following.Obiect(A)Development of high resolution measuring system of concentration fluctuations for multiple species，and the measurements of mixing·reactive field of multiple‘species by this systemWe developed the simultaneous measuring system of concentration fluctuations for 3species by the optical fiber with the diameter of 10u m，which is useful for the liid-phurtulmixeld field。In order to improve the accuracy of measurement，the new data processing technique to obtain the actual concentration signal by using the reference signal(In Case Of Concentration0)and measuring signal was suggested.The experimental apparatus for the two-dimensional turbulent reactive jet was also manufactured，and the concentration field without the reaction was measured by the new concentration measuring system。It is found that the fundamental statistics，e.g.，the mean concentration and the r.m.s。价值，etc.show the…More same profiles as those obtained by the former measuring system。So，it was concluded that the new system is useful for the concentration measurement in the turbulent diffusion field。Further，the measurements for the second-order chemical reaction field in the two-dimensional jet have been performed by using the former measuring system，and the understanding for the relationship between the chemical reaction and turbulence was promoted.Object(B)Numerical simulations of the diffusive·reactive fields by the stochastic differential and random-Fourier modes method.The simulation of the second-order chemical reaction field in the axisyetic reaction field in the stochastic differential@equation and random-Fourier modes method。The simulation of the second-order chemical reaction field in the axisyetic reaction field in the two。Practically，the experimental data for the moments up to the second order of the velocity PDF are specified，and the PDF method was applied to only the concentration field(we call this technique the semi-empirical PDF method)。In this simulation，the IEM model was used as the molecular mixing model.Consequently，it is confirmed that the concentration fluctuation fields for all the species relating to the chemical reaction were predicted successfully by this semi-empirical PDF method。On the other hand，the turbulent field around the two-dimensional aerofoil was simulated by the combined model of the random Fourier modes and the rapid distortion theory。It is found that the fluctuation velocity statistics，in particular the velocity spectra can be predicted well by this combined model。At present，the hybrid model of the random Fourier modes method and the molecular mixing model is being developed。Less：Less

The progress and results of the research are summarized in the following.Obiect(A) Development of high resolution measuring system of concentration fluctuations for multiple species, and the measurements of mixing ・ reactive field of multiple 'species by this systemWe developed the simultaneous measuring system of concentration fluctuations for 3 species by the optical fiber with the diameter of 10 u m, which is useful for the liquid-phase turbulent mixing field. In order to improve the accuracy of measurement, the new data processing technique to obtain the actual concentration signal by using the reference signal (in case of concentration 0) and measuring signal was suggested. The experimental apparatus for the two-dimensional turbulent reactive jet was also manufactured, and the concentration field without the reaction was measured by the new concentration measuring system. It is found that the fundamental statistics, e.g., the mean concentration and the r.m.s. value, etc. show the … More same profiles as those obtained by the former measuring system. So, it was concluded that the new system is useful for the concentration measurement in the turbulent diffusion field. Further, the measurements for the second-order chemical reaction field in the two-dimensional jet have been performed by using the former measuring system, and the understanding for the relationship between the chemical reaction and turbulence was promoted.Object(B) Numerical simulations of the diffusive ・ reactive fields by the stochastic differential equation and random-Fourier modes method.The simulation of the second-order chemical reaction field in the axisymmetric turbulent jet has been made by the Lagrangian probability density function method (PDF method). Practically, the experimental data for the moments up to the second order of the velocity PDF are specified, and the PDF method was applied to only the concentration field (we call this technique the semi-empirical PDF method). In this simulation, the IEM model was used as the molecular mixing model. Consequently, it is confirmed that the concentration fluctuation fields for all the species relating to the chemical reaction were predicted successfully by this semi-empirical PDF method. On the other hand, the turbulent field around the two-dimensional aerofoil was simulated by the combined model of the random Fourier modes and the rapid distortion theory. It is found that the fluctuation velocity statistics, in particular the velocity spectra can be predicted well by this combined model. At present, the hybrid model of the random Fourier modes method and the molecular mixing model is being developed. Less